Carbon-13 nuclear magnetic resonance (CMR) spectroscopy is an extremely rich source of structural data in organic chemistry, capable of rivalling or even surpassing proton magnetic resonance. In the research proposed here, we intend to develop this potential in the field of steroid chemistry as an application in a very important biomedical area. Cancer, arthritis and cardiovascular disease are only some examples where steroids play a crucial role and where steroid detection by new methods would be highly welcome. The factors which determine the CMR spectra of steroids are only modestly well understood. We have begun, and propose here to continue, a systematic study of families of closely-related steroids (keto- and hydroxy-androstanes and cholestanes) with the conviction that only through such a systematic study can the basic factors governing the CMR spectra of steroids be brought to light. We intend to quantify these factors as predictive rules which relate spectra to structures, and to develop computerized methods for using those rules to extract structural information from the CMR spectra of unknown steroids. We also propose to develop several chemical methods (derivatization procedures) for augmenting the information-content of such spectra.